It is normally difficult to prepare oxygen and nitrogen functional homo- and copolymers by Ziegler-Natta (Z-N) polymerization. The Lewis acid components (Ti and Al) of this catalyst will tend to complex with the non-bonded electron pairs on N and in preference to complexation with the pi electrons of the double bonds of the monomer. The net result is the deactivation of the active polymerization sites or the poisoning of the catalyst.
There are some reports of copolymerization of functional monomers with other alpha-olefins. For example, Clark, U.S. Pat. No. 3,492,277 (1970) has described a method of rendering polar vinyl monomers sufficiently unreactive to allow them to copolymerize with alpha-olefins without destroying the Z-N catalysts which consists of pretreating polar monomers with an organoaluminum compound.
Ester copolymers are especially useful because they are less reactive with the Z-N catalysts than some other oxygenated functionalities like--COOH. Thus, copolymers of esters, like methyl undecylinic ester, and short chain alpha-olefins, like ethylene and propylene, are described in Japanese patent application Nos. 57-152767, 57-188976, and 57-188997. Copolymers of methyl undecylinic ester and long chain alpha-olefins, e.g., 1-octene, are described in U.S. Pat. No. 4,518,757 (1984). Nevertheless, the levels of ester functional group incorporation for both of these copolymers remains low, i.e., &lt;5 mole percent. The incorporation for both of high levels of ester functionality up to the levels of completely (100%) functional homopolymers preferentially requires even more sterically hindered ester monomers, such as 2,6-di-phenyl phenyl 10-undecanonate ("Polymers and Copolymers from W-Functionality-Substituted Alpha-Olefins", Ph.D. thesis by M. D. Purgett, February, 1984, University of Massachusetts).
The corresponding low level acid copolymers (U.S. Pat. No. 4,523,929 and U.S. patent application No. 625,973, now U.S. Pat. No. 4,586,937) have been obtained by hydrolysis of ester copolymers. However, the ester polymer is not a particularly versatile intermediate. For example, it is not convenient to convert the ester functional polymers to other functional (e.g.,--OH, --NH.sub.2) polymers by simple mild chemical treatments.
Borane compounds are valuable intermediates in organic synthesis (H. C. Brown, "Organic Synthesis via Boranes", Wiley-Interscience, 1975). However, borane functional polymers are rare, being generally limited to only polydiene (e.g., polybutadiene or polyisoprene) backbones. Furthermore, polyborane polymers have previously been prepared by only post-polymerization modification processes, rather than direct polymerization (C. Pinazzi, J. C. Broose, A. Pleurdean and D. Reyo, Applied Polymer Symposium, 26, 73 [1975]). Polymer modification processes never achieve a 100% conversion.